This invention relates to an intranet system and in particular to an intranet server, a method of operating the intranet server and a memory medium for the intranet server.
Intranet systems are used in organizations, such as large corporations, that have a relatively large number of users who request resources via the internet from web servers on the world wide web (WWW). The resources requested generally include data contained in documents, web pages or other formats. A simple intranet system 10, shown in FIG. 1, has a proxy server 11 that receives the requests of a plurality of users C1, C2 and C3, obtains the requested resources from a web server 12 via the internet 13. These resources are then provided to the users.
The internet 13 is the network that forms connections or links L1 or L2 between intranet system 10 and web servers, such as web server 12. Links L1 and L2 are part of the internet. Links, such as L1 and L2, carry the brunt of the WWW traffic.
The stateless nature of the WWW servers can at times congest WWW traffic so much that the world wide web becomes the worldwide wait. As an example, consider the situation where users C1, C2 and C3 request the same web page from web server 12. The requested web page is sent over links L1 and L2 three times. This type of retransmission causes traffic congestion of information flow on the internet.
What is needed is a solution that reduces internet traffic congestion so as to allow a more rapid flow of information between the internet and its users.
An object of the present invention is to provide an intranet server that reduces internet traffic congestion by shadowing the information flow across an interface between the internet and an intranet system.
Another object of the present invention is to provide an intranet server that locally stores high usage resources and provides such resources to intranet users.
Still another object of the present invention is to provide a method of operating an intranet server to locally store high usage resources and provide such resources to intranet users.
Yet another object of the present invention is to provide a memory medium that causes an intranet server to locally store high usage resources and provide such resources to intranet users.
According to the present invention, an intranet server is provided to handle the requests for resources from one or more intranet servers or users that are downstream of the intranet server. An update means updates a usage count for each request from a downstream intranet server or a user for a resource. A maintaining means maintains the resource in a local memory if the usage count is equal to or greater than a threshold count value. A communication means sends an inquiry to an upstream intranet server or to a web server that is capable of serving the resource. This inquiry identifies the resource, whether the resource is stored in local memory, and the local version status of the resource. The response to the inquiry includes a current version status of the resource, a current version of the resource if the current version is more recent than the local version or if the resource is not stored in the local memory. The current version is stored in the local memory if the usage count is equal to or greater than the threshold count value. Server means serves the resource to the downstream intranet server or user that is currently requesting the resource.
The intranet server may also include a means for removing the resource from the local memory when a time out period has elapsed without receiving a request for the resource. In a more general sense, the resource is one of a plurality of resources with each having a separate usage count and time out or expiry value.
In another embodiment of the present invention, the intranet server has the capability of handling a priority resource that the operator of the intranet system considers mandatory for keeping in local memory of all intranet servers in the system. For this embodiment, the maintenance means maintains the priority resource in the local memory without regard for frequency of usage or elapsed time between requests for the priority resource. The serving means serves the priority resource, whenever received as new or revised from an upstream server or an intranet operator, to a downstream intranet server.
The intranet server of the present invention is capable of operating in a passive mode, an active mode or selectively in either mode. In a passive mode, user requests are handled by requesting resource status from an upstream intranet server or from a web server before servicing the user request. In the active mode, at least the intranet server that interfaces directly with the internet periodically checks the status of and updates the resources in its local memory to maintain at all times current versions of resources that meet the usage and time out requirements. For operation in the active mode, means are provided to periodically send an inquiry to a web server for each resource stored in its local memory. The inquiry identifies a resource and its local version status. The response will include a newer version, if any. Newer versions are substituted for older versions to keep the resources up to date. When a user request for a resource stored in the local memory is received, the resource is served from the local memory without an update inquiry to the internet.
According to an alternate embodiment of the present invention, a memory medium controls an intranet server that handles the requests of one or more downstream intranet servers or users for resources. The memory medium stores a program that configures the intranet server to have an update means that updates a usage count for each request from a downstream intranet server or a user for a resource. A maintaining means maintains the resource in a local memory if the usage count is equal to or greater than a threshold count value. A communication means sends an inquiry to an upstream intranet server or to a web server that is capable of serving the resource.
This inquiry identifies the resource, whether the resource is stored in the local memory and the local version status of the resource. The response to the inquiry includes a current version status of the resource, a current version of the resource if the current version is more recent than the local version or if the resource is not stored in the local memory. The current version is stored in the local memory if the usage count is equal to or greater than the threshold count value. Server means serves the resource to the downstream intranet server or user that is currently requesting the resource.
The intranet server may also include a means for removing the resource from the local memory when a time out period has elapsed without receiving a request for the resource. In a more general sense, the resource is one of a plurality of resources with each having a separate usage count and expiry value.
In another embodiment of the present invention, the memory medium controls the intranet server to handle a priority resource that the operator of the intranet system considers mandatory for keeping in local memory of all intranet servers in the system. For this embodiment, the maintenance means maintains the priority resource in the local memory without regard for frequency of usage or elapsed time between requests for the priority resource. The serving means serves the priority resource, whenever received as new or revised from an upstream server or an intranet operator, to a downstream intranet server.
According to the invention, the memory medium controls the intranet system to operate in the passive mode, the active mode or selectively in either mode. For operation in the active mode, means are provided to periodically send an inquiry to a web server for each resource stored in its local memory. The inquiry identifies a resource and its local version status. The response will include a newer version, if any. Newer versions are substituted for older versions to keep the resources up to date. When a user request for a resource stored in the local memory is received, the resource is served from the local memory without an update status inquiry to the internet.
A method embodiment of the present invention involves operating an intranet server that handles the requests of one or more downstream intranet servers or users by maintaining in a local memory those resources that are frequently requested. The method involves updating a usage count for each request from a downstream intranet server or a user for a resource. The resource is maintained in the local memory of the intranet server if the usage count is equal to or greater than a threshold count value. An inquiry is then sent to an upstream intranet server or to a web server that is capable of serving the resource. The inquiry identifies the resource, its storage status and its version status.
The response to the inquiry includes the current version status of the resource and a current version if the current version is more recent than the locally stored version or if the resource is not locally stored. If the response contains a current version of the resource, the current version is stored in the local memory if the usage count for the resource is equal to or greater than a threshold count value. The resource is then served to the downstream intranet server or user that requested the resource. Each resource in the local memory has a separate usage count and expiry value. After each use, the usage count is updated and the expiry value is reset.
In some embodiments of the present invention, a time out step is used. The time out step involves removing the resource from the local memory when a time out period has elapsed without receiving a request for the resource. That is, the time out period elapses when the expiry value equals the current date.
Another feature that may be used in the various embodiments of the method according to the invention involves the handling of a priority document. This involves the steps of maintaining a priority resource in the local memory without regard for frequency of usage or elapsed time between requests. When the priority resource is received as new or revised from an upstream server or an intranet operator, it is served to downstream intranet servers.
According to the invention, the method is operable in the passive mode, the active mode or selectively in either mode. For operation in the active mode, an inquiry is periodically sent to a web server for each resource stored in its local memory. The inquiry identifies a resource and its local version status. The response will include a newer version, if any. Newer versions are substituted for older versions to keep the resources up to date. When a user request for a resource stored in the local memory is received, the resource is served to the user directly or via any intervening downstream intranet servers from the local memory without an update status inquiry to the internet.